Library to access USB devices
This is a refactoring / rewrite of Christopher Klein's node-usb. The API is not compatible (hopefully you find it an improvement).
It's based entirely on libusb's asynchronous API for better efficiency, and provides a stream API for continuously streaming data or events.
Libusb is included as a submodule. On Linux, you'll need libudev to build libusb. On Ubuntu/Debian:
sudo apt-get install build-essential libudev-dev
Then, just run
npm install usb
to install from npm. See the bottom of this page for instructions for building from a git checkout.
Use Zadig to install the WinUSB driver for your USB device. Otherwise you will get
LIBUSB_ERROR_NOT_SUPPORTED when attempting to open devices.
var usb = require('usb')
Return a list of
Device objects for the USB devices attached to the system.
Convenience method to get the first device with the specified VID and PID, or
undefined if no such device is present.
Constant properties from libusb
Set the libusb debug level (between 0 and 4)
Represents a USB device.
Integer USB device number
Integer USB device address
Array containing the USB device port numbers
Object with properties for the fields of the device descriptor:
Object with properties for the fields of the configuration descriptor:
Open the device. All methods below require the device to be open before use.
Close the device.
Perform a control transfer with
data_or_length can be a integer length for an IN transfer, or a Buffer for an out transfer. The type must match the direction specified in the MSB of bmRequestType.
data parameter of the callback is always undefined for OUT transfers, or will be passed a Buffer for IN transfers.
Set the device configuration to something other than the default (0). To use this, first call
.open(false) (which tells it not to auto configure), then before claiming an interface, call this method.
Perform a control transfer to retrieve a string descriptor
Return the interface with the specified interface number.
List of Interface objects for the interfaces of the default configuration of the device.
Timeout in milliseconds to use for control transfers.
Performs a reset of the device. Callback is called when complete.
Return the InEndpoint or OutEndpoint with the specified address.
List of endpoints on this interface: InEndpoint and OutEndpoint objects.
Integer interface number.
Integer alternate setting number.
Sets the alternate setting. It updates the
interface.endpoints array to reflect the endpoints found in the alternate setting.
Claims the interface. This method must be called before using any endpoints of this interface.
Releases the interface and resets the alternate setting. Calls callback when complete.
It is an error to release an interface with pending transfers. If the optional closeEndpoints parameter is true, any active endpoint streams are stopped (see
Endpoint.stopStream), and the interface is released after the stream transfers are cancelled. Transfers submitted individually with
Endpoint.transfer are not affected by this parameter.
false if a kernel driver is not active;
true if active.
Detaches the kernel driver from the interface.
Re-attaches the kernel driver for the interface.
Object with fields from the interface descriptor -- see libusb documentation or USB spec.
Common base for InEndpoint and OutEndpoint, see below.
Object with fields from the endpoint descriptor -- see libusb documentation or USB spec.
Sets the timeout in milliseconds for transfers on this endpoint. The default,
0, is infinite timeout.
Endpoints in the IN direction (device->PC) have this type.
Perform a transfer to read data from the endpoint.
If length is greater than maxPacketSize, libusb will automatically split the transfer in multiple packets, and you will receive one callback with all data once all packets are complete.
this in the callback is the InEndpoint object.
Start polling the endpoint.
The library will keep
nTransfers transfers of size
transferSize pending in
the kernel at all times to ensure continuous data flow. This is handled by the
libusb event thread, so it continues even if the Node v8 thread is busy. The
error events are emitted as transfers complete.
Further data may still be received. The
end event is emitted and the callback
is called once all transfers have completed or canceled.
Emitted with data received by the polling transfers
Emitted when polling encounters an error.
Emitted when polling has been canceled
Endpoints in the OUT direction (PC->device) have this type.
Perform a transfer to write
data to the endpoint.
If length is greater than maxPacketSize, libusb will automatically split the transfer in multiple packets, and you will receive one callback once all packets are complete.
this in the callback is the OutEndpoint object.
Emitted when the stream encounters an error.
Emitted when the stream has been stopped and all pending requests have been completed.
Attaches a callback to plugging in a
Attaches a callback to unplugging a
To build from git:
git clone --recursive https://github.com/nonolith/node-usb.git cd node-usb npm install
To execute the unit tests, CoffeeScript is required. Run
Some tests require an attached USB device -- firmware to be released soon.
Does not support:
Note that the compiled Node extension includes Libusb, and is thus subject to the LGPL.